An amusement park that belongs to Mephisto Pheles. The main cast arrives to catch a ghost within this Ep12 title2

location. During that time, Rin meets Amaimon for the first time, and, after stealing Rin's demon sword, the two fight.

During their battle, Rin smashes the head of Mephisto's statue. To this, Amaimon states that Rin just "smashed his older brother's head". This is another proof leading to the fact that Mephisto is Rin's half brother as well.
Mepphyland also contains a secret base used by exorcists.

So u May find Amaimon here!
or just have run and relax here
(NEED MONEY TO PLAY GAMES )

Elle walked into Mepphyland excited,growing up in a small town she had never been to an amusement park. "Wow..." She felt like jumping around like a little kid but didn't want to scare the people around her. She wasn't sure what ride to go on first so she just kept walking around the park.